U.S. patent number 7,345,834 [Application Number 11/431,002] was granted by the patent office on 2008-03-18 for optical element holding system, barrel, exposure apparatus, and device manufacturing method.
This patent grant is currently assigned to Canon Kabushiki Kaisha. Invention is credited to Naoki Murasato.
United States Patent |
7,345,834 |
Murasato |
March 18, 2008 |
Optical element holding system, barrel, exposure apparatus, and
device manufacturing method
Abstract
A holding system for holding an optical element. The holding
system includes a ring-like inner holding member disposed at an
outer periphery of the optical element, for supporting the optical
element by use of at least a pair of pieces, and a ring-like outer
holding member disposed at an outer periphery of the inner holding
member and connected to the inner holding member at plural points.
The inner holding member has at least a pair of driving units with
an actuator, for supporting the optical element through the
actuators.
Inventors: |
Murasato; Naoki (Utsunomiya,
JP) |
Assignee: |
Canon Kabushiki Kaisha (Tokyo,
JP)
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Family
ID: |
36180476 |
Appl.
No.: |
11/431,002 |
Filed: |
May 10, 2006 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20060198036 A1 |
Sep 7, 2006 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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11247166 |
Oct 12, 2005 |
7116500 |
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Foreign Application Priority Data
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Oct 18, 2004 [JP] |
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2004-302388 |
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Current U.S.
Class: |
359/819; 359/811;
359/813; 359/822; 359/823; 359/830 |
Current CPC
Class: |
G02B
7/026 (20130101); G02B 7/028 (20130101); G02B
7/181 (20130101); G03F 7/70266 (20130101); G03F
7/70825 (20130101) |
Current International
Class: |
G02B
7/02 (20060101) |
Field of
Search: |
;359/819,822,823,827,830,811,813 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2001-343576 |
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Mar 2001 |
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JP |
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2001-343576 |
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Dec 2001 |
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JP |
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Primary Examiner: Spector; David
Assistant Examiner: Thomas; Brandi N.
Attorney, Agent or Firm: Fitzpatrick, Cella, Harper &
Scinto
Parent Case Text
This application is a divisional application of U.S. patent
application Ser. No. 11/247,166, filed Oct. 12, 2005, now U.S. Pat.
No. 7,116,500.
Claims
What is claimed is:
1. A holding apparatus for holding an optical element, said
apparatus comprising: a ring-like inner holding member disposed at
an outer periphery of the optical element and including a pair of
pieces configured to contact and to support the optical element,
said pair of pieces being disposed opposite to each other; three
connection members arranged at 120-degree pitches; a ring-like
outer holding member disposed at an outer periphery of said inner
holding member and configured to hold said inner holding member via
said plurality of connection members; and a pair of driving units
and a pair of contact members, said pair of driving units arranged
on said inner holding member and configured to support the optical
element, wherein each of said pair of driving units includes an
actuator and a contact member of said pair of contact members
configured to contact and to support the optical element, and is
configured to drive said contact member relative to said inner
holding member by said actuator to change a load applied from the
optical element to said contact member, said pair of contact
members being disposed opposite to each other, wherein said pair of
pieces and said pair of contact members are arranged at 90-degree
pitches, and said three connection members are arranged between
said inner holding member and said outer holding member and
symmetrically with respect to a line that connects said pair of
contact members with each other.
2. An apparatus according to claim 1, wherein said actuator
includes a bellows.
3. An apparatus according to claim 1, wherein said actuator
includes a piezoelectric device.
4. A barrel for accommodating an optical element therein, said
barrel comprising: a holding apparatus as defined in claim 1 for
holding the optical element.
5. A method of manufacturing a device, said method comprising steps
of: exposing a substrate to light by use of an exposure apparatus
as defined in claim 1; developing the exposed substrate; and
processing the developed substrate to manufacture the device.
6. An apparatus according to claim 1, wherein said pair of pieces
is disposed at positions opposed to each other, and said pair of
driving units is disposed at positions opposed to each other.
Description
FIELD OF THE INVENTION AND RELATED ART
This invention relates to an optical element holding system for
holding an optical element, such as a lens or a mirror, for
example. In another aspect, the invention concerns a barrel or an
exposure apparatus having such an optical element holding system,
and a device manufacturing method using such an exposure
apparatus.
In recent years, reduction projection type semiconductor exposure
apparatuses have used a short wavelength light source based on an
excimer laser, so as to meet further miniaturization in size of a
chip pattern and enlargement in density of a semiconductor chip.
The semiconductor exposure apparatus is an apparatus for
transferring an original (reticle) having a circuit pattern to a
substrate (silicon wafer), and it uses a reduction projection lens
by which the circuit pattern can be transferred by exposure onto
the substrate.
The projection lens must have an extraordinarily high resolving
power to make it possible to produce a very fine and highly
integrated circuit. To assure this, aberration of the projection
lens must be corrected to an extremely low level.
Conventionally, in such a projection lens system, optical elements,
such as lenses or mirrors, are held inside a lens barrel in
accordance with the following methods.
(1) A press fixing method in which an optical element is supported
along its entire circumference by use of a frame, such as a metal
frame, and, by pressing the frame from above by using a thread
screw ring, the optical element is press-fixed.
(2) A three-point support method in which an optical element is
supported at three points equidistantly distributed along its
circumferential direction.
Japanese Laid-Open Patent Application, Publication No. 2002-343576,
shows another method in which an elastic member is provided between
a metal frame, which directly supports an optical element, such as
a lens, and a supporting member disposed outside the metal frame.
According to this method, any distortion of the optical element due
to a temperature change or caused by assembling can be suppressed
by the elastic member.
In these methods, however, the surface shape of the lens, which is
supported along its entire circumference or at three points on the
circumference would be left deformed due to the weight of the lens
itself. There is no function for adjusting the surface shape of the
lens.
SUMMARY OF THE INVENTION
It is accordingly an object of the present invention to provide a
unique and an improved optical element holding technique by which
the shape of an optical element can be adjusted.
In accordance with an aspect of the present invention, there is
provided a holding system for holding an optical element,
comprising a ring-like inner holding member disposed at an outer
periphery of the optical element, for supporting the optical
element by use of at least a pair of pieces, a ring-like outer
holding member disposed at an outer periphery of the inner holding
member and connected to the inner holding member at plural points,
wherein the inner holding member has at least a pair of driving
units with an actuator, for supporting the optical element through
the actuators.
In accordance with another aspect of the present invention, there
is provided a barrel for accommodating an optical element therein,
comprising a holding system as discussed above, for holding the
optical element.
In accordance with a further aspect of the present invention, there
is provided an apparatus for exposing a substrate to light,
comprising a projection optical system through which the substrate
is to be exposed to the light, and a holding system, as discussed
above, for holding an optical element having a function for
directing the light.
In accordance with a yet further aspect of the present invention,
there is provided a device manufacturing method, comprising the
steps of exposing a substrate to light by use of an apparatus as
discussed above, developing the exposed substrate, and processing
the developed substrate to produce a device.
These and other objects, features and advantages of the present
invention will become more apparent upon a consideration of the
following description of the preferred embodiments of the present
invention taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a general structure of an optical
element holding system according to a first embodiment of the
present invention.
FIG. 2 is a fragmentary enlarged view, illustrating the structure
of an inner holding member 2 of the first embodiment shown in FIG.
1.
FIG. 3 is a fragmentary enlarged view, illustrating details of a
driving unit 3 of the first embodiment shown in FIG. 1.
FIGS. 4A and 4B are sectional views, respectively, for explaining
the disposition of the inner holding member 2 and elastic members 4
in the first embodiment shown in FIG. 1.
FIGS. 5A and 5B are sectional views, respectively, for explaining
the disposition of the inner holding member 2 and elastic members 4
in an alternative example of the first embodiment shown in FIG.
1.
FIG. 6 is a graph for explaining the amount of deformation of the
inner holding member 2 in the embodiment shown in FIG. 4.
FIG. 7 is a graph for explaining the amount of deformation of the
inner holding member 2 in the embodiment shown in FIG. 5.
FIG. 8 is a fragmentary schematic view for explaining the structure
of a driving unit in an optical element holding system according to
a second embodiment of the present invention.
FIG. 9 is a schematic view of a general structure of an exposure
apparatus to which the present invention is applied.
FIG. 10 is a flow chart for explaining the overall procedure of
semiconductor device manufacture.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will now be
described with reference to the attached drawings.
In a first embodiment of the present invention, an optical element
holding system of the present invention is applied to a projection
optical system for use in an exposure apparatus. However, it may be
applied also to an illumination optical system of an exposure
apparatus or to any other optical systems.
FIG. 1 is a perspective view of a general structure of an optical
element holding system according to the first embodiment of the
present invention.
The optical element denoted at 1 may have an optical function such
as reflection, refraction, diffraction, etc. Typically, it may be a
mirror, a lens or a diffraction grating. An inner holding member
denoted at 2 is held inside an outer holding member 5, and it is
arranged to fixedly hold the optical element 1 by use of a pair of,
or more, pieces 2a. The inner holding member 2 is provided with a
pair of, or more, driving units 3 arranged to apply at least one of
load and displacement to the optical element 1, such as a lens, for
example, to thereby control the attitude and/or surface shape of
the optical element 1. Any changes in attitude of the optical
element 1 due to deformation of the inner holding member 2 may be
cancelled by adjusting at least one of the amount of load and the
amount of displacement to be applied by the driving units 3.
The optical element 1 and the inner holding member 2 are in direct
contact with each other at pieces 2a shown in FIG. 2. The pieces 2a
are disposed at two points on the inner holding member 2, which are
disposed opposed to each other at a 180-degree pitch. There are
elastic members 4 with springs, which are disposed at plural points
between the outer holding member 5 and the inner holding member 2.
The elastic members 4 are arranged to absorb deformation in the
radial direction, but have high rigidity with respect to the
optical axis direction and the tangential direction.
Depending on the disposition of driving units 3, which are provided
mainly to adjust the shape of the optical element 1, the
disposition of the pieces 2a, as well as the number of them, may be
varied.
In the first embodiment, it is intended to deform the optical
element 1 into a symmetrical shape with a 90-degree pitch, and,
therefore, the driving units 3 are provided at two points with a
180-degree pitch.
Now, the method of holding the optical element 1 will be explained
in greater detail. The optical element 1 is in contact with the
pieces 2a, at its outer periphery of the optically effective region
thereof. Here, birefringence in which the refractive index changes
in dependence upon the direction of polarization of light incident
on the optical element 1 may occur in proportion to the load
applied to the optical element 1, and such birefringence may be
distributed radially from the point where the load is applied. In
consideration of this, the distance to the effective region of the
optical element 1 from the position where the optical element 1
contacts with the pieces 2a should preferably be made as large as
can be allowed by the weight of the optical element 1 or by the
tolerance in the lens production process. Furthermore, if a load is
applied perpendicularly to the optical axis, the amount of
birefringence production will be enlarged thereby. Taking this into
account, the position where the piece 2a contacts the optical
element 1 is at the bottom of face of the optical element 1. If the
holding force is insufficient and additional pieces should be
provided to supplement it, preferably, they should have a structure
for pressing the optical element 1 from either the bottom face or
top face thereof, not at the side face of the optical element
1.
Furthermore, each piece 2a should preferably be made to leave a
sufficiently small area to avoid the possibility of scratching the
optical element 1 surface, for example. This is because of the
necessity that the amount of deformation by the weight of the lens
should be made substantially equal to the result of deformation
calculation of CAE.
In order to obtain a desired holding force, the optical element 1
and the inner holding member 2 may be adjoined to each other by
filling, with an adhesive agent, the clearance therebetween along
their entire circumferences. This would assure stable holding. A
suitable adhesive agent should be chosen on that occasion, while
carefully taking into account the degassing characteristic, the
setting contraction characteristic, and the elasticity error
thereof. In this embodiment, a fluorine series two-liquid adhesive
agent was used.
The driving units 3 are provided at two mutually opposed points on
the inner holding member, and they are arranged to apply a desired
displacement and/or a desired load to the optical element 1.
FIG. 3 shows details of one driving unit 3. The optical element 1
is not shown there, for better understanding.
A welded bellows 3a is provided on the inner holding member 2 as an
actuator. By pressurizing the inside space of the bellows 3a by
using air, the bellows 3a can produce a force which is proportional
to the pressure. This force can be transmitted to the optical
element 1 via lever members 3b and 3c, whereby a desired surface
shape and a desired attitude are attainable. The lever member 3b
has a notch formed at the inner holding member 2 side thereof, to
obtain a suitable spring property. If the rigidity of that portion
is high, it necessitates the bellows 3a to produce an extra product
force. Therefore, the rigidity should preferably be lowered unless
the eigenvalue becomes too low.
The lever member 3c should provide a function for transmitting a
force to the optical element 1 without being distorted by the
product force produced by the bellows 3. For this reason, it should
preferably include a high-rigidity material, such as ceramics, for
example. The lever member 3c has been positioned by use of a spacer
so that, in the initial state thereof, it is placed close to the
bottom face of the optical element 1. The free end of the lever
member 3c has an R-shape so that it contacts the optical element 1
at a single point or along a line.
Depending on the position where the bellows 3a contacts the lever
members 3c, the leverage (lever ratio), that is, the ratio between
the product force of the bellows 3a and the load applied to the
optical element 1, varies. Thus, the relationship between the
pressure of the bellows 3a and the amount of displacement of the
optical element 1 may be measured beforehand, and the position of
the bellows 3a may be adjusted finely so as to provide an
appropriate leverage.
Next, the inner holding member 2 and the outer holding member 5,
which is at the outside of the projection system, will be described
in greater detail.
The outer holding member 5 serves to directly connect each unit
that holds an associated one of the optical elements of the
projection system, and thus, the flatness at its upper and lower
connecting surfaces as well as the circularity of its outer
configuration should have a highest precision. Therefore, use of a
high rigidity is preferable with respect to the machining. The
outer holding member 5 and the inner holding member 2 are connected
with each other by use of elastic members 4, at three points with a
120-degree pitch. Each elastic member 4 is made to provide an
appropriate resiliency in the radial direction due to its leaf
spring means, but to provide a high rigidity in the optical axis
direction and the tangential direction. With this arrangement, any
stress due to a difference in linear expansion coefficient between
the inner holding member 2 and the outer holding member 5, as well
as any stress resulting from the assembling, can be prevented from
being transmitted to the optical element 1 through the inner
holding member 2.
Regarding the rigidity of the elastic members 4, in order to well
assure evasion, it should be made lower than the rigidity of the
inner holding member 2. Furthermore, in order to avoid vibration
attributable to any external disturbance, the elastic members 4
should have a sufficiently high natural frequency. Each elastic
member 4 is connected to the inner holding member 2 at three points
with a 120-degree pitch.
Next, disposition of the elastic members 4 will be explained in
detail.
When a load is applied to the optical element 1 from the driving
unit 3, a reaction force as well is applied simultaneously to the
inner holding member 2. This causes deformation of the inner
holding member 2. Taking the outer holding member 5 as a reference,
such deformation might cause a tilt of the inner holding member 2
and the optical element 1.
In consideration of this and in order to minimize the tilt, it
would be preferable that a pair of (or more) pieces 2a and a pair
of (or more) driving units 3 are disposed alternately, and that
they have an even distance to an associated one of the elastic
members 4. More specifically, as shown in FIG. 4A, the elastic
members 4 should preferably be disposed symmetrically with respect
to a line that connects two opposed pieces 2a. Alternatively, as
shown in FIG. 5A, they may preferably be disposed symmetrically
with respect to a line that connects two opposed driving units
3.
Next, with respect to the disposition example of FIGS. 4A and 5A,
how the deformation of the inner holding member 2 causes a change
in attitude of the optical element 1 will be explained in
detail.
As regards the phase relationship between the four points that
support the lens and the three points of the elastic members that
support the metal frame or the inner holding member 2, it should be
determined carefully while taking into account the changes in
attitude of the optical element due to deformation of the inner
holding member.
At any point among the four points of the inner holding member,
being in direct contact with the optical element, the inner holding
member can deform due to a reaction force of the load applied to
the optical element. Particularly, at the fixed pieces which are at
two points out of the four points, adjustment is difficult to do
and deformation thereof would have an adverse influence upon the
attitude of the optical element. In consideration of this, the
fixed pieces at the two points should preferably be disposed to
have an even distance to the elastic members.
On the other hand, regarding the remaining two points of the
driving units, deformation of the inner holding member can be
cancelled by adjusting the output of the actuator.
When the bellows 3a is not producing any product force, the optical
element 1 is supported substantially at two points. As the product
force increases gradually, in the middle portion thereof, the
optical element 1 is supported at four points. As the product force
increases further, it is supported at two points, but inversely to
the initial support state.
Regarding the amount of deformation of the inner holding member 2
to be produced in these cases, deformation amounts in the case of
the FIG. 4A/4B structure are illustrated in FIG. 6, and deformation
amounts in the case of the FIG. 5A/5B structure are shown in FIG.
7.
In the example shown in FIG. 6, in the initial two-point support
state, the position of one of the pieces 2a, which is farther from
the elastic member, distorts downwardly due to the weight of the
optical element 1. As the product force increases further and
finally, the optical element 1 is supported at two points by the
driving units 3, the pieces 2a become free from the weight of the
optical element 1 and thus, they are deformed upwardly. The largest
deformation as compared with the initial state occurs at the piece
2a, which is farther from the elastic member 4. This causes a tilt
in the inner holding member 2 and the optical element 1, as
well.
As compared therewith, in the example shown in FIG. 7, since the
two pieces 2a are at equal distances from the elastic members 4,
deformations produced there would have an approximately even
amount. This hardly causes a tilt.
The largest deformation occurs at one of the driving units 3, which
is farther spaced from the elastic member 4. However, this can be
adjusted by increasing the product force of the bellows 3a only at
one side, thereby to correct the tilt of the optical element. In
consequence, when the leaf elastic members 4 are disposed in the
manner described with reference to the modified example of the
first embodiment, as shown in FIG. 5, while taking into account the
deformation amount of the inner holding member 2, aberration of the
optical element can be reduced to a minimum.
Next, the method of detecting changes in attitude and surface shape
of the optical element 1 will be explained.
The adjustment quantity for at least one of the load and the
displacement applied by the driving unit 3 may be
feedback-controlled on the basis of the position of a movable
portion in the driving unit 3 as can be detected by a sensor. This
sensor may directly detect displacement of the optical element
1.
For this detection, an electrostatic capacitance type sensor may be
used, for example. Alternatively, in this detection, any type of
sensor may be used, such as a laser interferometer, a strain gauge,
or a linear scale, for example, provided that it enables detection
being proportional to the attitude or surface shape of the optical
element 1. As a further alternative, a strain gauge may be provided
in the deformable portion of the driving unit 3 and it may be
semi-closed controlled.
The first embodiment will be explained here with reference to an
example wherein an electrostatic capacitance type sensor is used.
Regarding the points to be placed, sensors may be disposed at two
points of the driving unit 3. FIG. 1 illustrates sensor units 6. In
this example, although each sensor unit 6 is placed at a position a
few degrees rotated from the drive unit 3, this being for
convenience of disposition, preferably, it should be disposed
superposedly upon the driving unit 3 or closest to it. The member
for mounting the sensor may be adhered to the outside diameter of
the optical element 1 by using an adhesive agent. From the
standpoint of deformation and birefringence of the optical element
1, a loading method, such as using screws, is undesirable.
As regards the reference for the detection, the outer holding
member 5 may preferably be used as the reference. However, if the
reproducibility is assured, the inner holding member 2 may be used
as the reference, since it is less affected by external
disturbance.
Next, an optical element holding system according to a second
embodiment of the present invention will be described.
With reference to the driving unit 3 of the first embodiment, in
place of the bellows 3a, the actuator may comprise a piezoelectric
device (3d) having high rigidity and good response.
FIG. 8 illustrates a driving unit for the optical element holding
system according to the second embodiment of the present invention.
As regards the position of the piezoelectric device 3d, it may be
disposed below the lever member 3b, as in the case of the welded
bellows 3a of the first embodiment. Since, however, the
piezoelectric device 3d has a short stroke, there is a possibility
that the product force thereof is absorbed by the strain of the
lever member 3b. In consideration of this, preferably, the
piezoelectric device should be disposed below the lever member 3c.
This arrangement assures direct transmission of the displacement of
the piezoelectric device 3d to the optical element 1, without a
loss. The initial positioning of the piezoelectric device 3d may be
accomplished by use of a screw or a spacer. The piezoelectric
device 3d should be disposed as close as possible to the bottom
face of the optical element 1. Alternatively, the piezoelectric
device 3d may preferably be disposed so that it can abut against
the bottom face of the optical element when a small displacement of
a few microns or sub-micron order is applied to the piezoelectric
device 3d.
FIG. 9 shows an exposure apparatus for semiconductor device
manufacture, to which the present invention is applied.
This exposure apparatus can be used for the manufacture of
microdevices having a fine pattern formed thereon, such as
semiconductor devices (semiconductor integrated circuits, for
example), micromachines, or thin-film magnetic heads, for example.
In this exposure apparatus, exposure light (which may include
visible light, ultraviolet light, EUV light, X-rays, electron
beams, and charged particle beams, for example) as exposure energy
supplied from a light source 61 illuminates a reticle R (original),
and light from the reticle R is projected onto a semiconductor
wafer W (substrate) through a projection system having a projection
lens 62 (which may include a refractive lens, a reflective lens, a
catadioptric lens system, and a charged particle lens, for
example), whereby a desired pattern is produced on the
substrate.
The exposure apparatus includes a base table 51 having a guide 52
and a linear motor stator 21 fixed thereto. The linear motor stator
21 has a multiple-phase electromagnetic coil, while a linear motor
movable element 11 includes a permanent magnet group. The linear
motor movable portion 11 is connected as a movable portion 53 to a
movable guide 54 (stage), and through the drive of the linear motor
M1, the movable guide 54 can be moved in a direction of a normal to
the sheet of the drawing. The movable portion 53 is supported by a
static bearing 55, taking the upper surface of the base table 51 as
a reference, and also by a static bearing 56, taking the side
surface of the guide 52 as a reference.
A movable stage 57, which is a stage member disposed to straddle
the movable guide 54, is supported by a static bearing 58. This
movable stage 57 is driven by a similar linear motor M2, so that
the movable stage 57 moves leftwardly and rightwardly as viewed in
the drawing, while taking the movable guide 54 as a reference. The
motion of the movable stage 57 is measured by means of an
interferometer 60 and a mirror 59, which is fixed to the movable
stage 59.
A wafer (substrate) W is held on a chuck, which is mounted on the
movable stage 57, and a pattern of the reticle R is transferred in
a reduced scale onto different regions on the wafer W by means of
the light source 61 and the projection optical system 62, in
accordance with a step-and-repeat method or a step-and-scan
method.
It should be noted that the optical element holding system
according to the present invention also can be similarly applied to
an exposure apparatus in which, without using a mask, a circuit
pattern is directly drawn on a semiconductor wafer to expose a
resist thereon.
In one preferred embodiment of the present invention, the invention
is applied to a barrel for supporting one or more optical elements,
such as the barrel of the projection optical system 62 described
above, and the barrel may include at least one optical element
holding system described hereinbefore.
In another preferred embodiment of the present invention, the
invention is applied to a device manufacturing method, which may
include a process for producing a device by use of an exposure
apparatus as described above.
In accordance with these embodiments of the present invention as
applied to a barrel, an exposure apparatus and a device
manufacturing method, such as described above, the surface shape of
an optical element can be controlled and aberrations can be
corrected thereby. As a result, higher precision pattern transfer
is assured.
Next, an embodiment of a device manufacturing method, which uses an
exposure apparatus described above, will be explained.
FIG. 10 is a flow chart for explaining the overall procedure for
semiconductor manufacture. Step 1 is a design process for designing
a circuit of a semiconductor device. Step 2 is a process for making
a mask on the basis of the circuit pattern design.
On the other hand, Step 3 is a process for preparing a wafer by
using a material such as silicon. Step 4 is a wafer process, which
is called a pre-process, wherein, by using the thus prepared mask
and wafer, a circuit is formed on the wafer in practice, in
accordance with lithography. Step 5 subsequent to this is an
assembling step, which is called a post-process, wherein the wafer
having been processed at step 4 is formed into semiconductor chips.
This step includes an assembling (dicing and bonding) process and a
packaging (chip sealing) process. Step 6 is an inspection step
wherein an operation check, a durability check and so on, for the
semiconductor devices produced by step 5, are carried out. With
these processes, semiconductor devices are produced, and finally,
they are shipped (step 7).
More specifically, the wafer process a step 4 described above
includes (i) an oxidation process for oxidizing the surface of a
wafer, (ii) a CVD process for forming an insulating film on the
wafer surface, (iii) an electrode forming process for forming
electrodes upon the wafer by vapor deposition, (iv) an ion
implanting process for implanting ions to the wafer, (v) a resist
process for applying a resist (photosensitive material) to the
wafer, (vi) an exposure process for printing, by exposure, the
circuit pattern of the mask on the wafer through the exposure
apparatus described above, (vii) a developing process for
developing the exposed wafer, (viii) an etching process for
removing portions other than the developed resist image, and (ix) a
resist separation process for separating the resist material
remaining on the wafer after being subjected to the etching
process. By repeating these processes, circuit patterns are
superposedly formed on the wafer.
In accordance with these embodiments of the present invention, as
applied to an optical element holding system and a barrel, as
described hereinbefore, an optical system by which the shape of an
optical element can be adjusted, by which a change in attitude of a
lens can be suppressed, or by which a desired optical performance
is assured, is provided.
Furthermore, in accordance with these embodiments of the present
invention as applied to an exposure apparatus and a device
manufacturing method, as described hereinbefore, higher precision
pattern transfer or pattern formation is assured.
While the invention has been described with reference to the
structures disclosed herein, it is not confined to the details set
forth and this application is intended to cover such modifications
or changes as may come within the purposes of the improvements or
the scope of the following claims.
This application claims priority from Japanese Patent Application
No. 2004-302388 filed Oct. 18, 2004, which is hereby incorporated
by reference.
* * * * *